Based on the book "The Midwich Cuckoos" this is a pretty nifty little movie about children with odd powers. I'd almost think it was an influence on Stan Lee when he created the X-men a few years later. I liked it a lot more than the sequel "Children of the Damned". The moody black and white photography helps, as do those creepy English voices of the kids.
Because "we know all your secrets..." The parody was so effective in the Simpsons, since it had such good material to start with. I recommend seeing this version of the movie. The sequel is OK, and I've never seen the remake.